The invention relates to a device for the vertical and automatic wedging in C-shaped slideways of a vehicle removable seat. It relates more especially to removable seats comprising, on the one hand, means of positioning in longitudinal slideways fixed to the floor of the vehicle and, on the other hand, retaining hooks able to collaborate with the internal returns of the slideway when the seat is subjected to impact energy and, in addition, means allowing their longitudinal position to be adjusted, with locking in the chosen position.
In these seats, the seat-part structure is secured to an underframe formed of two subassemblies, namely a right-hand one and a left-hand one, each comprising a rigid sideplate the lower part of which is set out in the form of a runner to run in a C-shaped slideway, and, borne by this runner:
catches, collaborating with returns, teeth or notches of the slideway,
retaining hooks,
and an actuator connected to control means borne by the seat and to return means, for controlling the movements of the catches and of the hooks.
In spite of the care taken in manufacturing the components of the underframe, in assembling these components and in fitting the slideways, the build-up of manufacturing tolerances may, in certain seat/slideway combinations, form vertical clearances which, even when the seat is wedged and locked in its slideways, encourage vertical movements of small amplitude but which generate noise and discomfort to the occupant.
The invention provides a device for the automatic vertical wedging of the underframe of a seat in its slideways.
This wedging device comprises:
a vertical journal mounted to rotate in a bearing of the underframe,
a member for wedging in terms of vertical translation, connected in terms of rotation to the lower end of the journal and having, when viewed from above, a rectangular overall shape the shortest dimension of which is less than the width of the groove of the C-shaped slideway and the longest dimension of which is greater than this width, so as to be able, in the wedged position, to sit under the internal returns of the slideway,
a spring constantly returning the wedging member to its wedging position,
a means for causing the journal to pivot against the action of its return spring into a position in which the wedging member can be engaged in the groove of the corresponding slideway,
and at least one helical ramp which, rotating as one with the journal, collaborates with a fixed complementary bearing surface to move the wedging member vertically and bring it into contact with the returns of the slideway.
Thus, each, right or left, subassembly of the seat is equipped with a wedging member which is normally in a wedging position but which, when the runners with which this seat is equipped are introduced into the slideways, is brought into a position of introduction into these slideways. As soon as the seat is positioned therein and the operator stops actuating the journal control means, the return spring associated with each of them returns them to their rest position, in which position the wedging member is arranged transversely to the groove of each slideway. During this rotation, the helical ramp of each journal comes to bear against a complementary bearing surface and causes the journal to move vertically, this having the effect of bringing the wedging member into contact with the underside of the returns of the slideway in which it is arranged, thus ensuring positive connection between the seat and its slideways.
The result of this is that, whatever the functional clearances resulting from the spread of manufacturing tolerances, the underframe is connected to the slideways to eliminate the generation of any noise and any vertical movements, and also horizontal ones, because of the clearance between the catches and the housings accommodating them.
Advantageously, the means controlling the rotation of the journal comprise a vertical finger projecting upward from the head of this journal and an inclined ramp, single or double, formed in a slide controlling the retraction movements of the catches and of the hooks of each of the runners.
Thus, at the same time as the operator actuates the means arranged on the seat to bring the catches and the hooks into the position of retraction, for example before engaging the runners of the underframes in the C-shaped grooves of the slideways, he commands the pivoting of the journal against the action of its return means and allows the wedging member to move from its wedging position to its retraction position allowing it to be engaged in the slideway.
In one embodiment of the invention, the journal has a head under which the helical ramp is formed while the complementary bearing surface collaborating with this ramp is formed on the end face of a flange formed at the upper end of a vertical bearing for the journal, this bearing being attached in the underframe and prevented from rotating with respect to it.
In another embodiment, the helical ramp is formed on the upper face of each of the ends of the wedging member and collaborates with the straight internal face of the C-shaped returns of the slideway.